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    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
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    <script>
        // 用于查看数据或变量的数据类型，进而实现相关的判断、处理...
        var a = "abc" ;

        var aType = typeof(a) ;

        console.log(aType);
        


    </script>
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